Question 1

The breakdown of glucose to pyruvate by a cell is an example of what type of reaction?

Accepted Answer

A)  anabolic
B)  aerobic
C)  catabolic
D)  apoptotic
E)  synthetic C

Question 2

________ is the mechanism by which a phosphate is directly transferred to ADP to form ATP.

Accepted Answer

Substrate-level phosphorylation

Question 3

Anabolic pathways

Accepted Answer

A)  increase molecular order.
B)  are endergonic.
C)  decrease entropy.
D)  can be stimulated by anabolic hormones.
E)  All of the above are correct. E

Question 4

Positron emission tomography (PET)of a patient who has consumed the radiotracer fluorodeoxyglucose reveals tumors because

Accepted Answer

A)  any radioisotope accumulates in tumor cells.
B)  cancer cells accumulate fluorodeoxyglucose because they consume excessive amounts of glucose through aerobic glycolysis.
C)  the fluorodeoxyglucose labels cells killed by the PET treatment.
D)  the fluorodeoxyglucose labels only the normal tissue because cancer cells cannot metabolize glucose.
E)  the fluorodeoxyglucose associates with the anti-tumor drugs being used for treatment.

Question 5

Allosteric regulation of key enzymes in glycolytic and gluconeogenesis pathways may involve each of the following except

Accepted Answer

A)  activating the enzyme activity.
B)  inhibiting the enzyme activity.
C)  binding of the allosteric regulator molecule to directly compete with substrate binding in the enzyme active site.
D)  binding of the allosteric regulator molecule to a site on the enzyme other than the active site.
E)  Any of the above may be involved.

Question 6

The gross output of ATP from glycolysis is ________,whereas the net output of ATP is ________.

Accepted Answer

A)  2; 1
B)  4; 2
C)  4; 1
D)  6; 4
E)  2; 4

Question 7

During the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate and phosphoenolpyruvate,a phosphate group is added to ATP to generate ATP.The mechanism for ATP production in this reaction is

Accepted Answer

A)  substrate-level phosphorylation.
B)  product-level phosphorylation.
C)  oxidative phosphorylation.
D)  anabolic phosphorylation.
E)  aerobic phosphorylation.

Question 8

Isotopic labeling of a specific substrate carbon with 13C,which has an extra neutron,is particularly useful for investigating biochemical pathways because

Accepted Answer

A)  the presence of the radioisotope greatly accelerates the pathway,which makes it easier to study.
B)  the position of the labeled carbon can be traced through products of the pathway to characterize the pathway reactions.
C)  the radioisotope blocks each pathway at a specific step.
D)  the radioisotope readily exchanges neutrons so that all neighboring carbons become labeled and easier to detect with NMR.
E)  radiolabels generally are easier to track in cells than fluorescent labels.

Question 9

Compare and contrast ethanol and lactic acid fermentation pathways.

Accepted Answer

The answer of Compare and contrast ethanol and lactic acid...

Question 10

Galactosemia is a disease caused by a genetic defect that affects an individual's ability to correctly metabolize galactose for use in the glycolytic pathway,but has no effect on metabolism of starch and glycogen,or on glycolysis.Galactosemia results in high galactose levels in the blood and accumulation of galactose-1-phosphate in the tissues.
a)If you were a physician treating a person with this genetic disorder,in addition to galactose,what other dietary sugar would you recommend the patient not consume to avoid high galactose levels in the blood?
b)Why would infants be more likely than adults to have high blood galactose levels associated with galactosemia?
c)Suggest a reason for the observation that galactosemia is more common than fructosemia?
d)Propose possible candidates for the defective enzyme that causes galactosemia.

Accepted Answer

The answer of Galactosemia is a disease caused by a...

Question 11

How many enzymes are involved in glycolysis of glucose to pyruvate?

Accepted Answer

A)  3
B)  6
C)  8
D)  10
E)  12

Question 12

When studying carbohydrate metabolism in a newly identified bacterial species,you find the bacteria grow exclusively on the carbohydrate sucrose.
a)Hypothesize whether the bacteria use glycolysis or a novel pathway for harnessing energy.
b)For what enzyme would you assay the bacteria to test your hypothesis?

Accepted Answer

The answer of When studying carbohydrate metabolism in a newly...

Question 13

Each of the following can be the final electron acceptor in bacterial aerobic or anaerobic respiration except

Accepted Answer

A)  sulfur.
B)  hydrogen ions.
C)  Fe3+.
D)  oxygen.
E)  pyruvate.

Question 14

Oxidation is the removal of ________,which usually is accompanied by removal of protons in a process called ________ in biological systems.

Accepted Answer

The answer of Oxidation is the removal of ________,which usually...

Question 15

Which of the following is a coenzyme?

Accepted Answer

A)  NAD
B)  NADP
C)  FAD
D)  CoA
E)  All are coenzymes.

Question 16

The phosphate group that is removed from PEP when it becomes pyruvate

Accepted Answer

A)  is added to NAD+ to make NADP.
B)  is released as Pi.
C)  is added to ADP to make ATP.
D)  is added to glyceraldehyde-3-phosphate to make 1,3-bisphosphoglycerate.
E)  is added to fructose-6-phosphate to make fructose-1,6-bisphosphate.

Question 17

Which of the following is not a product of fermentation?

Accepted Answer

A)  lactate
B)  CO2
C)  ethanol
D)  NAD+
E)  glycogen

Question 18

In animal cells,glycolysis and gluconeogenesis are regulated to ensure that both processes are reciprocally active.This regulation involves each of the following compounds except

Accepted Answer

A)  NADH.
B)  fructose-2,6-bisphosphate.
C)  AMP.
D)  acetyl CoA.
E)  cAMP.

Question 19

An anabolic reaction usually

Accepted Answer

A)  yields energy.
B)  requires energy.
C)  involves no change in energy.
D)  is degradative,regardless of energy change.
E)  decreases molecular order.

Question 20

Human erythrocytes have no mitochondria.The rare inherited metabolic disorder that results from pyruvate kinase deficiency is particularly destructive to erythrocytes and causes hemolytic anemia.
a)Suggest a reason for increased erythrocyte death in the presence of pyruvate kinase deficiency.
b)Suggest a reason for the low incidence of mutations in human glycolytic enzymes.

Accepted Answer

The answer of Human erythrocytes have no mitochondria.The rare inherited...

Exam 9: Chemotrophic Energy Metabolism: Glycolysis and Fermentation